URI

Abstract

Human primary visual cortex (V1) has long been
associated with learning simple low-level visual discriminations
[1] and is classically considered outside
of neural systems that support high-level cognitive
behavior in contexts that differ from the original
conditions of learning, such as recognition memory
[2, 3]. Here, we used a novel fMRI-based dichoptic
masking protocol—designed to induce activity in
V1, without modulation from visual awareness—to
test whether human V1 is implicated in human observers
rapidly learning and then later (15–20 min)
recognizing a non-conscious and complex (secondorder)
visuospatial sequence. Learning was associated
with a change in V1 activity, as part of a
temporo-occipital and basal ganglia network, which
is at variance with the cortico-cerebellar network
identified in prior studies of ‘‘implicit’’ sequence
learning that involved motor responses and visible
stimuli (e.g., [4]). Recognition memory was associated
with V1 activity, as part of a temporo-occipital
network involving the hippocampus, under conditions
that were not imputable to mechanisms associated
with conscious retrieval. Notably, the V1 responses
during learning and recognition separately
predicted non-conscious recognition memory, and
functional coupling between V1 and the hippocampus
was enhanced for old retrieval cues. The results
provide a basis for novel hypotheses about the
signals that can drive recognition memory, because
these data (1) identify human V1 with a memory
network that can code complex associative serial
visuospatial information and support later nonconscious
recognition memory-guided behavior (cf.
[5]) and (2) align with mouse models of experiencedependent
V1 plasticity in learning and memory [6].